Paste with Ctrl+V · drag files here · or Open — as many as you like
PNG · JPEG · WebP · GIF — or a saved .json project
Properties apply to the selected element, or to defaults for new elements when nothing is selected. Sizes are in board pixels — set once for your usual screenshot size.
Runs entirely in this file — no network calls, no telemetry, no accounts, no cloud. One self-contained HTML file: your projects and exports never leave this machine. The one exception you control: the Donate buttons open your browser to an external payment page — only when you click them; nothing else ever leaves this machine.
Verify it: hash this file (e.g. certutil -hashfile on Windows or shasum -a 256 elsewhere) and compare against a copy you trust.
Nothing here needs the internet to run. Once the page is open, every tool, template and export works with the network switched off, and keeps working for as long as the tab stays open. No part of your images, text or projects is ever uploaded — there is nowhere for it to go.
The limitation: that only holds while the page is already loaded. If you close the tab and later return to arrowbox.app with no connection, it will not open — your browser still has to fetch the page from the web the same way it fetches any other. There is no background installer or hidden cache doing this for you.
For a copy that works forever: press Ctrl+S (⌘+S on a Mac) and save as Webpage, HTML only. That single file is the whole app. Keep it on a USB stick, an air-gapped machine, anywhere — open it and it runs, with no connection, indefinitely. It will not expire or phone home.
Two small differences when running a saved file rather than the website: Save As and Open use ordinary downloads instead of a file picker (browsers restrict that API on local files), and Copy to clipboard may be blocked — Export always works. Everything else behaves identically.
Exports are flattened: in a PNG, JPEG or PDF the redacted pixels are genuinely destroyed, with no original left underneath to recover. Share exports freely.
The limitation: a saved project (.json) is re-editable by design, so it embeds the original image with each redaction sitting on top as a movable element — anyone with that file can slide one aside and read what was under it. Treat a project file exactly as you would treat the original image.
Available for hire. Enquiries and bug reports welcome — arrowbox88111@outlook.com. Mail opens in your own email client; nothing is sent from this file.
Paste a screenshot (Ctrl+V), drag image files in, or click Open — annotate — Ctrl+S exports. As many images as you like on one board.
The pin button keeps any tool armed after placing; Esc disarms back to Select.
Click an element (outlined shapes: click the border). Drag empty space for a marquee — callout arrows and locked elements are never caught. Shift+click toggles. Ctrl+A selects all. Ctrl+G groups (clicking any member selects the whole group), Ctrl+Shift+G ungroups. Align and z-order live in the panel; arrow keys nudge 1 px, Shift+arrows 10 px.
Double-click a text box or callout to edit. Enter = new line. Select a range to format just that range from the panel; Ctrl+B / Ctrl+I toggle bold / italic (with a collapsed caret they hit the word at the caret). Esc commits — a brand-new box left empty is discarded. Boxes hug their text until you resize them by hand; double-click a resize handle to trim the height to the text — the width is kept, and the height keeps following the text from then on.
Opened images tile to the right of existing content; a pasted image lands in your current view — the zoom never changes — steering clear of what’s already on screen. Corner handles resize keeping the aspect ratio; opacity is in the panel. Crop: select an image, click Crop, drag a region — Shift+click Crop removes the crop and restores the pre-crop framing. The Locked checkbox pins an image so it can't be dragged, resized or marquee-selected.
The Template… dropdown inserts a ready-made board — Damage Claim, Incident Report, SOP / Step Guide or Before / After — as ordinary editable elements on a white sheet; one Ctrl+Z removes the whole insert. Style presets save the current style under a name and apply to the selection, or to the defaults for new elements when nothing is selected. The theme and panel buttons toggle light / dark and the properties panel; preferences persist on this machine.
Export (Ctrl+S) uses the format dropdown — PNG · JPEG · PDF, with a quality pick for JPEG / PDF. A bare image exports at its exact size; once marked up, the export adds a 20 px margin around the content. With 2+ elements selected, only the selection exports (a “-selection” file — the original is never overwritten). On Chrome / Edge, PNG / JPEG exports save over the same file in place once one is known (open via Open, or Save As once); PDF always saves as a new file. Toggle Save As to pick a location every time. Save Project (Ctrl+Shift+S) writes a re-editable .json with the original images embedded — redactions stay editable elements in it, so send exports and keep projects to yourself. Copy (Ctrl+Shift+C) puts the flattened image on the clipboard.
Thank you — donations keep ARROWBOX free, offline and BS-free. Payment happens on PayPal in a new tab; this file never handles money or sees your details.
Arrowbox is a free image markup tool that runs entirely in this page: paste a screenshot (Ctrl+V), drag files in, or click Open — then annotate with arrows, callouts, text, highlights and auto-numbered step stamps, blur or pixelate the sensitive parts, and export a PNG, JPEG or PDF with Ctrl+S. No upload, no account, no watermark, no telemetry.
Redactions here are real: exports are flattened, so the pixels under a blur, pixelation or black-out are destroyed in the file you share — there is no hidden layer for a recipient to peel back. And nothing you load ever leaves your machine: the page makes zero network calls, enforced by its Content-Security-Policy and verified by an automated build check.
Works offline: save this page (Ctrl+S, “HTML only”) and it keeps working from a USB stick or an air-gapped machine, indefinitely. Click the ◢ ARROWBOX mark in the toolbar for the full privacy statement, user guide and every keyboard shortcut. Free — donation-supported. © 2026 Hei Ng.